Answer
Yes. The confidence interval constructed in item (b) is entirely above the confidence interval constructed in item (d) and both were constructed under a 95% level of confidence. Also, this is a designed experiment.
Work Step by Step
The researchers controlled the explanatory variable (the type of treatment) and used the same cyclists in both cases. The results show a substantial difference between the lower bound obtained in sports-drink treatment (201.5 kilojoules) and the upper bound obtained in the placebo treatment (194.5 kilojoules).
